Method and apparatus for cooling rods



y 1950 J. E. OBRIEN 2,516,248

METHOD AND APPARATUS FOR COOLING RODS Filed Aug. a, 1946 v e Sheets-Sheet 1 \q. N R 3mm James E 0 Zrz'en July 25, 1950 J. E. OBRIEN METHOD AND APPARATUS FOR COOLING RODS 6 Sheets-Sheet 2 Filed Aug. 3, 1946 JQJ'Zf-SE 031127;,

8 ggy July 25, 1950 J. E. OBRIEN 2,516,248

METHOD AND APPARATUS FOR COOLING RODS Filed Aug. 3, 1946 6 Sheets-Sheet 3 glvvum Janus-E 0251 y 1950 J. E; O'BRIEN 2,516,248

METHOD AND APPARATUS FOR COOLING RODS Filed Aug. 3, 1946 6 Sheets-Sheet 4 July 25, 1950 J. E. OBRIEN METHOD AND APPARATUS FOR COOLING RODS 6 Sheets-Sheet 5 Filed Aug. 3, 1946 y 1950 J. E. OBRIEN 2,516,248

METHOD AND APPARATUS FOR COOLING RODS Filed Aug. 5, 1946 6 Sheets-Sheet 6 20/1 260 A A: I

My invention relates Patented July 25, 1950 A METHOD AND APPARATUS FOR COOLING RODS James E. OBrien, Baltimore, Md., assignor to Bethlehem Steel Company, a corporation of Pennsylvania Application August 3, 1946, Serial No. 688,234

1 in general to the processing of metal rods, and more particularly to a method and apparatus for the controlled cooling of coils of hot rolled rods of iron and steel.

In the manufacture of ferrous rods and rod products such as wire, it has been the usual practice to conduct the hot freshly rolled rod from the finishing roll pass through a water-cooled tubular guide which initially cools the rod somewhat, then through a water-eliminating apparatus provided with jets of air to blow the water from the surface of the rod, and then to form the rod into coils on a reeling mechanism. From ;ture well above the upper critical range, or at about 2000 F. to 1800 F., a hard black'coating of scale, chiefly ferroso-ferric oxide (Fe3O4), will normally form upon the hot rod surface, particularly on the inner parts of the coil which cool very slowly. Cooling with water alone below 1500 F. is generally impracticable, because of the increased danger of embrittlement due to a too drastic quench.

But since the amount of scale formed varies in accordance with the time and temperature of exposure to the atmosphere, and scale formation stops below 1100 F., controlled rapid cooling of the. rod in air to below that point efiects savings, both in weights of iron and acid, and in cleaning time, which when applied to the large tonnages produced by the usual rod mill are important and worthwhile. Moreover, the quality and uniformity of grain structure, particularly of high carbon steels, are notably improved, the pearlite instead of coarse lamellar plates being in the form of small uniform grains which facilitate subsequent heat treatment anddrawing the rod into wire;

Among the objects of my invention in the controlled cooling of hot rolled rods, therefore, are the following: reduction of scale loss; quicker, cheaper cleaning of rods due to .less scale; more uniform physical properties from outside to center of coils; and better drawing properties in high carbon grades. Other and further objects, purposes and ad vantages of my invention will appear in the following detailed description, in the attached six sheets of drawings, and in the appended claims. In the drawings:

I Figure 1 is a top plan view of the coiling end of conveyor androd cooling apparatus;

11 Claims. (01.148-2155) Fig. 2 is a section'ta en along the line 22 of Fig. 1;

Fig. 3 is a top plan detail view of the blower and hood motor for one pair of conveyor lines;

Fig. 4 is a top plan View of the finishing rolls, guides and delivery troughs to the cooling reels; Fig. 5 is a, section through the reel and the cooling station ofone of the conveyors, on the line 6,6 of Fig. 1;

Fig. 6 is a fragmentary section, also on the line 6-6 of Fig. 1, showing in detail the op,- eratingmechanism of, the hood and dampers;

Fig. 7 is a top plan detail view of the take-up device attached to the hood lifting cable; 1 '1 I Fig. 8 is a diagrammatic view of one of th conveyor lines; Fig. 9 is a section taken on the'line 9 9-of Fig 5; V,

I Fig. 10 is a section on the'line Ill-ID of Fig. 9; Fig. 11 is a detail view of the reel pin control valvepand Fig. 12-is 'a wiring diagram of the electrical system by which the movements of the reels, the conveyors, the blowers and the dampers-are automatically coordinated and controlled. Referring now to Fig. 4, the. numeral l designates the last or finishing pair of rolls in a con tinuous rodmill, said rolls being provided for example with the pair of grooved passes 2, from which passes 'thehot rolled rod 3 is directed-by pivoted guides 4 through curved water-cooled pipes or troughs 5 and water eliminatcrs 6; to one of the four .reels 1. As shown in Fig.1, each oi said reels 1 is at the head of a separate conveyor 8 and is enclosed therewith in a muffle casing 9. The reels and conveyorsare arranged in parallel lines on a suitable concrete foundation Ill, and are of substantially identical construction,- so that the description of one such line willlmake plain-the operation of all. 1 While-othertypes 'of reels or coilers may be used if desired, the reel] which I have shown-in Fig. 5 is of the conventional laying type, in which a rotating delivery pipe ll, driven by gearing l2 and shafting [3 from an external power source, coils the rod 3 on the stationary bottom trough plates of the conveyor 8. The rod coil I6, is formed horizontally in the usual manner, between concentric rows of vertical pins Ilmounted on a. circular plate [8, which pins are raised ,be-e fore coiling and lowered when the coil has been completed through apertures inthe bottom trough plates I4 by the operator admitting steam or;

other fluid throughthe distributor valve 19 and;

the pipes 20 or :21 ,tothe desired end; of the two.

way fluid pressure cylinder 22, thereby actuating the piston 23 connected by bifurcated piston rod 24 to said plate 18. Reel switch 25 controls the movement of the conveyor motor 26 as will hereinafter be described.

The bottom trough plates M of said conveyor are slotted centrally at 21 to receive an endless conveyor chain 28 carried on sprocket wheels 29, chain-driven by motor 26, and provided with regularly spaced spurs 30 adapted to engage the coil l6 and advance it to initial stop position-15,,

where the operator may inspect itfand thence through a pivoted fla door 3| to the second stop position 32. J

When the coil 15 has reachedthe-second position, the conveyor motor 26 is stopped and the lid-actuating mechanism 33 shown'in Fig.6 lowers a heavy deflector lid 34 onto the top of said coil. The lid-actuating mechanism 33 comprises an induction motor 35 connected by a shaft 36 to gear-reducer 31 having a crankarm38 on one end of its shaft 39, said motor and gear reducer being mounted on' the platform lll supported by I-beam columns -'4'-l Said crank arm 38 is connected by wire rope or cable 42, ha'vin'gterminal loops 43 formed around thimbles 4'4 and held by 'clips 45, to 'a springtake-up device 46. As shown in Fig. 91, sai'd take-up device comprises an eyebolt 41, on which a perforated pin 48 is slidably mounted tindiyieldably held against "the washer 49 and -ni1ts'59 by the=coil spring fil washers52, and nuts 53. 'Sai'd pin 48 -is pivoted in theclevised upper arm'bf bell crank '54,'which-'i'si centrally pivoted in support '55 mounted on bracket-56 'on conveyor :cbver '5l. The lower arm 58 of said bell crank 54 is pivoted to clevised connecting r'od 59 'which in turn is pivoted tothe deflector lid 34.

The other end of reducer shaft 39 is connected by means of a coupling 60 to shaft -6 l journaled iii-hearings '52 andterm-inatin'g' in crank arm 63 connected by link 64 and lever 65 to damper 66 in branc'h air duct '61, said damper being adapted to ileave the duct 63 open while deflector "-lid 34 is down. Air from one of the inotor-driven fans or blowers 68 m'ounted on theplatform it is blown through main ductBQ, branch duct 61, grating -11) and floor plate opening 'H into the "center a of the coil 1 9 and-outward'throi'igh its' cum/muons. l l'iedflect'or lid 34"prevents' the escape of air ever'thetop of the'coil andforces the air toflow through all the strands of thecoil insteadjthereby cooling the "rod uniformly and also blowing off some loose scale. Theexhaus'teir'leaves at the rea'r of the casing 9. I When the coil 16 is sufiiciently cooled and ready for further travel, the induction -motor 35 is reversed, the lid 34 is raised, the 'damper G5 shuts oil the airyand the process is repeated wi th the next coil. The step-bystep' progress of the coil on the chain' conveyer fterminates at the raised kick-off end 12, whereit is trans- {erred to a hook "conveyor 13 for subsequent processing.

Eabh of thetwo blowers 68- is normally kept "continuously, and furnishes the air used to cool the 1 rod eons [6 '"on' two or the four conveyors' 8. When one conveyori's in motionfhowever, its damper fi 6 diverts "the air-tram that particular-"conveyor, 'so'thatthe run air from its blower is directedto the other con'veyorfserve'd by' the same blower. -As soomas-themotion "of ma'conveyor line stops, and the deflector lid 34 is lowered the damper 66' iso' 'oefied so that the; normar situation of one'jblower furnishing airtotwo coils r6' simuitaneously is resumed.

- ill geared to driving motor 26, relay 82, relay series resistance 83, and starting resistance 84, and relay series coritactors 85, 86, Bl, 88 and 89.

The deflector lid motor 35, preferably of the reversible alternating-current squirrel-cage induction type with shunt brake 90, is controlled I by two hatchway type upper and lower limit switches "9i and 92 operated by a cam 93 on reducer shaft 39, relays 94 and 95, reversing starter relays "9'6 and 9 'a'nd*cut-'ou'tswitch 98in reel -operaltoi s*pulpit 99.

--Assume;that the deflector 'lid 34 is down, the reelpins H are up, and'rod is being 'coiled on the reels The line switch ll-and field switch 18 are closed. The re'el pin switch 25 is open, the shut-oifswitch -is closed, and the limit switch 8! is in the 'positionshown in the diagram. The hood motor-upper limit switch 9! has its contacts It? open-andcontacts I'M closedas'shown. The hood motor lower limit switch 92 "has its contacts lll2open.

When 'the coiling is complete, the reel pulpit operator lowers the reel pins "i l as previously described, and ree'l pin switch then closes.

The master switch -19 is then 'manually placed-in p'ositi'on to close centacts I 83. "The direct-"curren't then passes from the positive -terz'nin'al l 94 through i the reel switch "'25 through contacts N3 of master switch 19fthrough contacts I04 of sh'u'tor: j-swit'ch 81! through contacts [9 5 of limit switch 8! through contacts *l-flll 'olf "upper "limit switch 9i through coilflllfi of relay 94"to"negat'iv'e terminal 1'01. Th'e relay contacts "l 08 then close, energizing the rai'se-c"ont"actor '96 and completing the alternating current controrcircu'it to "the induction motor "35. "As soon its the deflector lid 34 is raisedashort distanc'e thebontac'ts 192 of the lower limit switch 92 close; "and 'when"the hood is fully raised the opening df contacts P0! of {the upperlimit"switch"9l opens re1ay94which stops'the lid motor '35.

The -closing-of 'contacts 1-00 of said upper limit switch 9| completes the pdsitiveco'ritrbl circuit motor "26 in Understood fm'anner, the series contactors 85586, and 88 closing in desired-sequence when the 'currentsin their operatin circuits dropfbelow certain definitefvalues as the resistance 83 is thrown into the ci'r'cu it and the coils of the contactors are shorted out, thereby shorting out-inturn the section's of'the "star-ting resistance '84. The field switch f8 is provided us shown with an auxiliary'blajde or connecting 1 a discharge resistance across the shunt field when breaking that circuit.

After the conveyor "8 has traveled a "fixed 'distance, the limit switch 8.! trips and stops'the motion by opening'contacts I05. "At 'thesame'ti'me this occurs, the contacts P09 and "11.0 close, and

contacts I H open, The closing of 'c'ontacts'llfi completes t he 'mas'ter switch circuit'to therelay which closes and energizes the'lowercoritactor 91 of the motor 35. When the deflector "lid 34 reaches its bottom position andthe Hamper 66 is open, the lower limitswit'ch'92 opens contacts 102 to stop the motion, and ,air from the blower ,68 passes through the coil [6. ,After the deflecof shut-oil switch 80, I09 of limit switch BI, and

HH of upper limit switch 9i. After the deflector lid 34 is raised, the conveyor moves and stops, and the'circuit to relay 95 is set up through contacts l l I of limit switch 8 I If the operator at the kick-off pulpit requires an emergency stop, he operates the shut-off switch 80, the stop being indicated on a signal light H4 controlled by an auxiliary contact H5. If it is desired to operate the conveyor without the deflector lid 34, the latter is raised and cut-out switch 98 in reel pulpit 99 is opened. The conveyor can operate at any time when the deflector lid 34 is in the raised position. Conventional electrical safety-devices, such as the fuses H6, circuit breakers Ml and 1 l8, thermal overload switches H9, I20 and HI, and overload relays I22 and H3, are also provided, as shown in Fig. 12, and function in their usual and well understood manner.

Rod which has been cooled by this air blast system has only a minimum amount of very light scale, which scale breaks off evenly in cleaning. The resultant smoother surface has special advantages for rod that is intended to be drawn into wire.

Although I have hereinabove shown and described my invention in considerable detail, I do not wish to be limited to the exact and specific construction so shown and described, but I may also use such substitutions, modifications, or equivalents thereof as are embraced within the scope and spirit of the invention, or as are pointed out in the appended claims.

Having thus described my invention; what I claim as new and desire to protect by Letters Patent is:

1. The method of reducing scale formation on hot ferrous rod which comprises the steps of forming the hot rod at temperature over 1500 F. into a coil, advancing the hot rod coil to a predetermined stopping position, lowering a lid onto the coil, blowing air into the center of the coil and outwardly through its convolutions until the coil is cooled below approximately 1100 F., lifting the lid from the cooled coil, and removing and further processing the coil.

2. The method of cooling ferrous rods which comprises taking a hot rolled rod after it leaves the finishing roll pass at a temperature in the neighborhood of 1800 F., briefly water-cooling the rod to a temperature above 1500 F., eliminating residual water from the rod surface, forming the rod into a coil, conveying the coil in a step-by-step movement to a first position for inspection, advancing the coil to a second position, covering the top of the coil, blowing air laterally through the convolutions of the coil until the temperature of the coil is reduced at least to 1100 F., removing the covering from the coil, and then conveying the coil for further cooling.

3. The method of cooling ferrous rods which comprises taking a hot rolled rod after itf-leaves the finishing roll pass at a temperature at-lea'st as high-as the critical range, initially water-000L- ing the rod to substantially 1500" F., forming the rodinto coils, conveying each coil in a step-by.- step movement, covering the top of the coil, and then while the coil is in a stationary position blowing air from the inside of the coil laterally through the convolutions of the coil until the temperature of the: coil is reduced to approximately 1100 F.

4. An apparatus for cooling hot ferrous rod comprising a reelwhereby the rod is-formed into a coil, a conveyor whereon the coil is moved, means responsive to arrival of said coil at :an intermediatev position for automatically. stopping the conveyor, means operable by the stopping-of the, conveyor to apply a cooling medium tow-the coil, and means operable by resumed movement of the conveyor to divert the cooling medium. from the coil.q 1 l l a i 5. An apparatus for cooling hot ferrous. rod comprising means for forming the hot rod into a coil, associated means for advancing the hot-:rod coil, means for stoppin the coil at an .interme diate. position,means for placing. a lid on the coil, means for blowing air upwardly and out.- wardly through the coil, means for removing the lid from the coil, and means for resuming the advance of the coil to discharge positiona- 6. An apparatus for cooling hot ferrous rod comprising pairs of conveyors extending parallel with the line of delivery of the rod, an independent coiling device associated with each conveyor, a blower for each pair of conveyors, a pair of ducts connected to said blower, each duct having an outlet beneath a conveyor of said pair, a vertically reciprocable lidabove each outlet, a damp-er in each duct, and coacting means actuated when a rod coil is positioned above the outlet to lower the lid thereon and open the damper to blow air through the coil.

7. An apparatus for cooling hot ferrous rod comprising a plurality of pairs of conveyors extending parallel with the line of delivery of the rod, an independent device associated with each conveyor for forming the rod into a coil, a casing enclosing said conveyor and coiling device, a flap door closing each conveyor from its coiling device, a grating beneath each conveyor, a movable lid above each grating, a blower for each pair of conveyors, ducts connecting said blower to the gratings of said pair of conveyors, a damper in each duct, and automatic means to lower the lid and open the damper when a coil is positioned on the conveyor directly above the grating.

8. An apparatus for cooling hot ferrous rods comprising means for rolling the rod, means for initially cooling the rod with water immediately after the rolling operation, reeling means for coiling the rod, a conveyor electrically controlled for imparting a step-by-step movement to the coil, a lid adapted to be lowered to cover the coil while the coil is held stationary on the conveyor, means for blowing air into the center of the coil to force the air under pressure laterally through the convolutions of the coil, and automatic means electrically controlled for raising and lowering the lid.

9. An apparatus for cooling a hot rolled ferrous rod comprising means for initially cooling the rod with water immediately after the rolling operation, a reeling device for coiling the rod, means for lowering and raising the reeling device after the coiling operation, a conveyor electrically conhailed for imparting a step-by-step movement to the coil, a lid adapted to be lowered to cover the ooiliwhlle the coil is held stationary on the conweyor, :means for blowing a blast of air into the center of the coil to force air under pressure through "the convolutions of the coil, means electrically controlled :for automatically raislng'and lowering "the lid, means iior holding the conveyor stationary when the lid is lowered, and means for discharging the coll'from the conveyor.

"10. an apparatus .for cooling :h ot ferr'ous rod comprising pairs :of conveyors extending parallel thelin'e of delivery of the rod, an independent iflflilin'g device "associated with each conveyor to: :co'iling the rod, electrically controlled means *Icr (imparting a step-by-step movement for each conveyor, .a trough for each conveyor having a bottom 'wall, a 'blowerifo each pair of conveyors,

a .pair or Fducts connected to said blower, :eac'h comprising a-pluralit'y of pairs of con-veyors'em tending parallel with the line of delivery of rod, an independent coiling :device assoclated'ivlth each conveyor for forming :the mod into a coil, a casing having a bottom wall enclosing each conveyor and coiling \clev-ice, electrically controlled means for imparting a step-by-step movementtc each conveyor, a grating in "the bottom wail of the casing of each conveyor-l, a movable lid above eachigrating, :a blower for each nair of conveyors, ducts connecting said blower to the gratings of :said .pair of conveyors, .a damper :in :each duct, and automatic means electrically actuated to lower the lid and open the damper when a coil is positioned am the conveyor above the grating.

JAMES OfBH-IEN.

REFERENCES CITED The following references are of record in th file of this patent: UNITED STATES PATENTS 1Statz et a1. V Jan; 27 19.42 

